1. Field of The Invention
The invention relates to a cylindrical optics assembly and a method making the same, and particularly to a new arrangement of such cylindrical assembly which may significantly simplify assembling thereof.
2. The Related Art
A cylindrical optics assembly with a GRIN lens, such as a collimator, can be use with at least an optical fiber for collimating the dispersive light occurring around an output end of such fiber. The collimated light may be efficiently and controllably utilized for the transmission or testing purpose. Understandably, the lens can transform the output of the light according to a Sine/Cosine format by changing the thickness of the lens to meet the desired one such as a spot light instead of the aforementioned collimated light.
As shown in FIGS. 1 and 2, the structure of a traditional cylindrical optics assembly 100 uses a lens 102, e.g., a GRIN lens, closely faces to an output end of an optical fiber 104. Because the optical fiber 104 is so tiny and feeble, a capillary 106 designedly attachably surrounds the output end of the fiber 104, and then the capillary 106 with the associated fiber 104 is very very carefully and gently positioned with regard to the GRIN lens 102 commonly within a tubular fastening holder 108. There are two reasons to provide a capillary 106 surrounding the end of the fiber 104. The first reason is to reinforce the end of the fiber 104 for easy controllably positioning the fiber 104 end with regard to the corresponding lens 102. The second reason is to function as an adaptor to largely increase the diameter around the end assembly portion of the fiber 104 and have such end assembly portion of the fiber 104 and the lens 102 in a compliance manner, i.e., the outer diameter or circumferential configuration of these two parts complying with each other. It should be noted that the fiber 104 has a 150 .mu.m diameter and the lens 102 generally has a 1800 .mu.m diameter, and there is a relatively large difference therebetween. This is the reason why the capillary 106 should be attached to the end of the fiber 104 for functioning as an adaptor, thus resulting in the end assembly portion of the fiber 104 through the associated capillary 106 commonly defining a dimension generally very close to the diameter of the lens 102. Therefore, it is relatively easy to controllably adjust the relative positions between the lens 102 and the end of the fiber 104 within the holder 108. Under some certain situations, due to the limitations of the specification of the existing lens 102 and fiber 104, both the fiber 104 and the lens 102 should use their respective adaptors on their exterior for achievement of circumferential compliance therebetween.
After the mutually/relatively positions of both capillary 106 and GRIN lens 102 have been attained, both of them are respectively glued by adhesive 110 to the inner surface of the fastening holder 108, thus finalizing an optics assembly which has a connected fiber and emits the desired either the collimated or the focused spot light. It can be understood that the tubular fastening holder 108 provides an inner diameter relatively larger than outer diameters of both the capillary 106 and the GRIN lens 102 for forming a sufficiently large clearance C therebetween whereby both of the capillary 106 and the GRIN lens 102 can adjustably move with regard to each other in the fastening holder 108 in all directions until they relatively reach the corresponding mutually aligned positions and glued with regard to the outer holder 108 at their final positions.
It should be appreciated that to adjust the mutually aligned positions of both of the capillary 106 and the GRIN lens 102 is a very difficult matter because it involves five parameters, i.e., X, Y and Z coordinate axes of a rectangular coordinate system and .alpha. and .beta. angles of a polar coordinate system. It is very common to take several hours to get the truly aligned relative positions of both the capillary 106 and the GRIN lens 102 in the holder 108. Also, even after true positions of both parts are obtained, the gluing procedure for fastening both parts to the outer holder 102 should be taken very carefully and time-consuming for not influencing the difficultly obtained true positions of both parts in the holder 108.
Therefore, it is an object of the invention to provide a simplified structure of the cylindrical optics assembly which allows easy assembling for alignment between the GRIN lens and the corresponding fiber, while still maintaining the requirement of precision of such alignment therebetween.